JACKSON, Miss. -- A cancer doctor and her former billing agent pleaded guilty Friday for their parts in a multimillion-dollar health care fraud case in which prosecutors said old needles were reused, chemotherapy drugs were diluted and public and private insurance was overbilled millions.

Dr. Meera Sachdeva, who founded the Rose Cancer Center in the south Mississippi town of Summit in 2005, pleaded guilty in U.S. District Court in Jackson to one count of health care fraud and two counts of making false statements.

Standing before the judge wearing black-framed glasses and shackles with her long black hair draped over an orange prison jumpsuit, the 50-year-old doctor looked straight ahead while her lawyer denied the most serious allegations that she diluted chemotherapy drugs.

One of her patients, 76-year-old Wayne Spring, watched intently and left the court disappointed. He told The Associated Press that he contracted two bacterial infections from the clinic and now has regular tests for HIV and hepatitis. He beat cancer, but the ordeal left him shaken.

"She liked to have killed me," Spring said. "I'm disappointed in the whole thing."

Sachdeva faces up to 20 years in prison. If convicted on all counts she could have faced up to 165 years in prison and more than $3.2 million in fines.

Spring's son, Kirk, wanted Sachdeva to admit to the more serious allegations and was disappointed most of the charges were dropped.

"She's going to pay her due. No matter what happens in here, she will pay her due one day," he said just outside the courtroom.

Sachdeva's lawyer, Robert McDuff, told the U.S. District Judge Daniel P. Jordan III that his client admits to billing for treatments that happened when she was out of the country, but denied diluting drugs. Doctors are required to be in the office when chemotherapy treatments are given. The bills to Medicaid and Medicare alone were for about $15.1 million.

McDuff had no comment after the hearing.

Assistant U.S. Attorney Scott Gilbert said Sachdeva billed for more drugs than she had bought from suppliers.

The Mississippi Health Department closed the clinic in July 2011 because of "unsafe infection control practices" after 11 patients were hospitalized with the same bacterial infection. The scare led officials to test nearly 300 cancer patients for infections such as HIV. The department has said none of the patients tested had blood-borne viral infections related to the clinic's care. However, a civil lawsuit claims at least one patient died about the time the clinic was shut down from HIV he contracted there.

Sachdeva, a naturalized citizen from India, has been held without bond since her arrest last August because she's considered a flight risk. Prosecutors say she had considerable assets, including bank accounts in her native country, despite the seizure of about $6 million.

Monica Weeks, who handled the clinic's billing from her Ridgeland firm, Medical Billing Group, pleaded guilty to conspiracy to commit fraud. The prosecutor said she provided Sachdeva with information that was used to falsify nine patients' charts ahead of an audit and lied to investigators about documents she removed from the clinic.

"The conduct to which Monica Weeks pled guilty today involved nine patient charts and less than $20,000," her lawyer, Cliff Johnson said in a statement.

"The facts the government recited to the court as the basis for Monica's plea do not include any action which jeopardized the health or safety of a single patient. Ms. Weeks has accepted responsibility for her actions, and she and her family look forward to putting this entire ordeal behind them," Johnson said.

Sentencing for both women is Oct. 1.

Office manager Brittany McCoskey pleaded guilty May 17 to one count of false statements and awaits sentencing.

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